As depicted in FIG. 1, conventional cooling for power electronics is based on heat conduction through multiple layers that are in contact with a heat sink that convects the heat to the ambient. These layers typically consist of a silicon power device or “chip” that is soldered to a conventional Direct Metallization (DM) layer, usually copper. The DM layer is soldered to a copper base plate/heat spreader. The copper base plate/heat spreader is connected via a thermal interface material, such as thermal grease, to an aluminum heat sink. The typical conventional power inverter design is based on a two-dimensional layout where all the heat generating devices are located in a single plane. The heat transfers perpendicularly to this plane to the heat sink.
This conventional serial heat flow path—from chip into solder layer into DM layer into solder layer into copper base plate/heat spreader layer into thermal interface layer and finally into heat sink—introduces significant thermal resistance. As the thermal resistance in the heat flow path increases, so does the size, weight, cost and manufacturing complexity of the heat sink to accommodate it. A more efficient structure for transferring heat from the power electronics chip is needed.